1. Field of the Invention
This invention relates to a method for setting image processing conditions for scanning and processing an image, such as scanning start/end positions, calibration position, highlight point and shadow point positions, in an image scanning and processing apparatus such as an electronic process scanner external to said image scanning and processing apparatus. This invention also relates to a visual monitoring device for visually reading positions on the scanning surface related to said setting.
2. Description of the Prior Art
In an electronic process scanner, it generally takes a long time to set the original on the input cylinder and set various image processing conditions, such as color correction, optimally according to the original (hereinafter, this process is called "setup"). It also takes a considerably long time to actually scan the original following setup so as to obtain a process film in which the original is separated in colors and printed. Therefore, the job efficiency is extremely poor if the setup and actual original scanning process are carried out in series. Conventionally, two scanning input unit sets were provided, for example, and they were alternately connected to a common output unit (film printing and processing unit), so as to carry out the setup of the next original in the other scannng input unit. In this parallel processing system, however, althrough the productivity was improved, it was very uneconomical because it needed two expensive and complicated input unit sets for scanning the original and processing the image. Besides, when it is attempted to realize a simpler setup method without using the electronic scanner itself, in order to set up the various coorditions including the position data perfectly, it is necessary to match perfectly the system of coordinates at the time of setting up and that of actual scanning process. If these systems of coordinates cannot be matched, the coordinates to indicate the points on the original, e.g. printing start point and end point, must be set on the scanner itself. This is a great drawback for the enhancement of operating rate of the scanner and improvement of efficiency of the scanner operator.
Devices for visually reading position on the scanning surface such as shown in FIG. 1 to FIG. 3 are known. FIG. 1 refers to a structure in which a reading device is assembled into the scanning head 1 of a process scanner, and a reflector 3 is inserted, when reading, into the optical axis of the pickup lens 2 (a photoelectric conversion element such as photomultiplier, which is not shown, is located at a remote position). When positioning the scanning head 1 at a desired position of an original 5 adhered on an original cylinder 4, the scanning head 1 and the original cylinder 4 are coarsely moved so that light from a light source (not shown) may come near the desired position, and a very tiny spot on the original 5, magnified by the pickup lens 2, is focused on a ground glass 6 through the reflector 3. A register mark used as a positioning target is printed on the ground glass 6, and the operator can fine-adjust the positioning while observing the image on the ground glass 6 magnified through the lens 7. In this method, however, the diameter of the spot, being related with the spot of the pickup of the scanner, is as small as 0.7 mm; the magnification factor is very high, and it is in practice not known in which position of the original 5 the image on the ground glass 6 is located. Thus, this structure is not suited to positioning because it is originally composed for use in focusing. The scanning head accordingly is positioned approximately by the operator directly observing the illuminated part of the original 5 by the light spot from the light source (not shown).
The conventional devices shown in FIGS. 2(a) and 2(b) are convenient for visually reading the end position directly by bringing a needle-shaped pointer 8 close to the original 5. However, reading errors may occur due to the position of the eye unless the original 5 and the pointer 8 are extremely close to each other. However, when the pointer 8 is too close, the expensive original 5 may be damaged.
In the conventional device shown in FIG. 3, there are two target plates 9a and 9b in which markers are drawn and a lens 10 is arranged into line. When the markers on the target plates 9a and 9b overlap, the markers, magnified by the lens 10, are read visually by the operator. In the device, however, since it is required to aim at a position on the original 5 by matching the two markers, the eye position is limited and the device accordingly is difficult to use. Also, use of the device tires the operator because the eye focusing position differs between the target plates 9a and 9b and the original 5 under magnification by the lens 10.